■ Switch the call between the headset and mobile
To switch the call from the headset to a connected device, press and hold
the multifunction key for about 4 seconds (the headset switches off), or
use the keys of your device. To switch the call back to the headset, switch
on the headset (and connect it to your paired device), or press and hold
the multifunction key for about 2 to 3 seconds (when the headset is on).